探讨慢性阻塞性肺疾病患者体重指数与肺功能指标的相关性

目的 研究COPD患者体重指数(BMI)与肺功能指标的相关性,为COPD患者治疗护理提供新的依据.方法 随机选取2010年1月至2011年10月来我院呼吸内科就诊的男性COPD患者115例,按BMI分成三组:低BMI组50例,正常BMI组50例,超BMI组15例,检测肺功能指标:深吸气量(IC)、第一秒用力呼气容积(FEV1)、用力肺活量(FVC)、一秒率(FEV1/FVC).结果 超BMI组IC、FEV1、FVC比正常BMI组明显增高(P＜0.05),正常BMI组IC、FEV1、FVC又比低BMI组明显增高(P＜0.05),三组FEV1/FVC无明显差异(P＞0.05).相关性分析提示BMI与IC、FEV1、FVC呈正相关,与FEV1/FVC无相关性.结论 改善COPD患者营养状况,控制理想的体重指数,可以有效地改善肺功能,提高生活质量.     

老年人的气道高反应性分析

目的探讨老年人的气道反应性特点,为老年气道高反应性在临床上的应用提供依据.方法临床疑诊为气道反应性增高且肺功能正常或接近正常的病人142例,以磷酸组织胺吸入作支气管激发试验评价气道高反应性.结果激发试验总阳性率为38.0%(54/142),其中男性的阳性率略高于女性(46.8% vs 31.3%,P>0.05).气道高反应性的程度分布极轻度占31.5%,轻度占42.6%,中度占25.9%.基础肺功能(FEV1%预计值)与气道反应性增高(PD20FEV1)在老年病人中呈低度正相关(r=0.259,P=0.05),基础肺功能损害较重者其气道反应性增高也越明显.结论老年人的气道反应性相对较低,气道高反应性程度以极轻度和轻度为主.     

187例咳喘老年人的气道高反应性测定

目的　探讨咳喘老年人的气道反应性特点 ,为老年人气道高反应性 (BHR)在临床上的应用提供依据。　方法　临床疑诊为气道反应性增高且肺功能正常或接近正常的老年患者 187例 ,以二磷酸组织胺吸入作支气管激发试验 ,评价其气道高反应性。　结果　激发试验阳性者 6 9例 ,阳性率为 36 9% ,其中男性 38例 ,女性 31例。BHR的程度分布 :极轻度者 2 2例 ,占 31 9% ;轻度者 30例 ,占 43 5 % ;中度者 17例 ,占 2 4 6 % ;本组病例中未见重度BHR者。第 1秒用力呼气量 (FEV1)占预计值的百分率与使FEV1下降 2 0 %所需组织胺的累积激发剂量 (PD2 0 FEV1 His)呈低度正相关 (r =0 2 77,P <0 0 5 )。　结论　本组疑诊为BHR的老年患者其支气管激发试验阳性率较低 ;气道反应性增高程度以极轻度和轻度为主 ,基础肺功能与气道反应性增高在老年患者中呈低度正相关 ,基础肺功能损害较重者其气道反应性增高也较明显     

成人过敏性难治性支气管哮喘患者血清维生素D水平的相关临床研究

目的 研究成人难治性过敏性支气管哮喘(简称哮喘)患者血清维生素D水平以及和肺功能、总免疫球蛋白E、气道反应性,总免疫球蛋白E和气道反应性的相关性研究.方法 选择有过敏性哮喘病史的患者,测定肺功能及舒张试验,阳性者采用Uni CAP系统测定总免疫球蛋白E及特异性IgE,采用酶联免疫法测定体内维生素D主要的储存形式25羟维生素D3[25(OH)D3]含量,比较25(OH)D3水平和肺功能、总免疫球蛋白E、气道反应性的相关性以及总免疫球蛋白E和气道反应性相关性.结果 哮喘患者血清25(OH)D3含量明显低于正常值(23.10±23.15),且男女之间差异无统计学意义;血清25(OH)D3与FEV1％pred呈明显正相关(r=0.428,P＜0.01);和总免疫球蛋白E无明显相关性(r=-0.265,P＞0.01);和气道反应性呈明显负相关(r=-0.559,P＜0.01);总免疫球蛋白E和气道反应性呈明显正相关(r=0.578,P＜0.01).结论 成人难治性过敏性哮喘患者血清25(OH)D3明显低于正常水平,对于总免疫球蛋白E虽然无明显影响,但明显影响着患者的肺功能及气道的反应性.     

成人过敏性难治性支气管哮喘患者血清维生素D水平的相关临床研究

目的研究成人难治性过敏性支气管哮喘(简称哮喘)患者血清维生素D水平以及和肺功能、总免疫球蛋白E、气道反应性,总免疫球蛋白E和气道反应性的相关性研究。方法选择有过敏性哮喘病史的患者,测定肺功能及舒张试验,阳性者采用UniCAP系统测定总免疫球蛋白E及特异性IgE,采用酶联免疫法测定体内维生素D主要的储存形式25羟维生素D3[25(OH)D3]含量,比较25(OH)D3水平和肺功能、总免疫球蛋白E、气道反应性的相关性以及总免疫球蛋白E和气道反应性相关性。结果哮喘患者血清25(OH)D3含量明显低于正常值(23.10±23.15),且男女之间差异无统计学意义;血清25(OH)D3与FEV1%pred呈明显正相关(r=0.428,P0.01);和总免疫球蛋白E无明显相关性(r=-0.265,P0.01);和气道反应性呈明显负相关(r=-0.559,P0.01);总免疫球蛋白E和气道反应性呈明显正相关(r=0.578,P0.01)。结论成人难治性过敏性哮喘患者血清25(OH)D3明显低于正常水平,对于总免疫球蛋白E虽然无明显影响,但明显影响着患者的肺功能及气道的反应性。     

成人支气管哮喘患者血清25-羟维生素D_3水平及其与肺功能的关系

目的了解成人支气管哮喘(简称哮喘)患者血清25-羟维生素D3[25(OH)D3]水平,为哮喘的治疗提供新的策略。方法收集门诊确诊哮喘患者162例,通过电化学发光法检测患者血清25(OH)D3浓度,以德国JAEGER肺功能仪检测哮喘患者用力肺活量(FVC)、第1秒用力呼气容积(FEV1),计算第1秒用力呼气容积占预计值百分比(FEV1%pred)、FEV1/用力肺活量。根据患者FEV1情况行支气管激发或舒张试验。对25(OH)D3与乙酰甲胆碱PD20FEV1(PD20MCH-FEV1)、FEV1增加值、FEV1增加率的相关性进行分析。结果哮喘患者血清25(OH)D3浓度均低于正常参考值。支气管激发试验中,25(OH)D3与PD20MCH-FEV1呈正相关(P0.001,r=0.73);支气管舒张试验中,25(OH)D3与FEV1增加值及增加率均呈正相关(r分别为0.53、0.59,P值均0.01)。结论成人哮喘患者血清25(OH)D3浓度比正常值低;血清25(OH)D3浓度与哮喘患者气道高反应性呈负相关,与β2受体激动剂作用后气道阻塞的改善情况呈正相关。     

脉冲振荡法测定在COPD患者中的应用研究

目的探讨脉冲振荡法(IOS)测定在慢性阻塞性肺疾病(COPD)患者中的临床应用。方法选择100例COPD患者(COPD组)和50例健康体检者(对照组),比较二者常规肺功能检测及IOS检测结果,并分析两种方法的相关性。结果与对照组比较,COPD组用力肺活量(FVC),第1s用力呼气容积(FEV1)、第1 s用力呼气容积/用力肺活量百分比(FEV1/FVC%)、FEV1实测值/预计值(FEV1/Pre%)均显著降低(P0.05);COPD组共振频率(Fres)、呼吸总阻抗(Zrs)、5 Hz时呼吸总阻抗(Z5)、5 Hz时电抗(X5)、总气道阻力(R5)、中心气道阻力(R20)、周边气道阻力(R5-R20)、中心阻力(Rc)及周边阻力(Rp)均较对照组显著升高(P0.05);Fres、R5、R20、R5-R20与FEV1、FEV1/FVC%、FEV1/Pre%均呈显著负相关(P0.05)。结论 IOS测定可较好地反映COPD患者气道阻力的变化,联合常规肺功能测定可更好地判断COPD患者的气道堵塞及病情变化,尤其适用于老年患者。     

腹腔镜袖状胃切除术后肥胖患者肺功能变化与炎症介质及脂肪因子的相关性分析

目的探究肥胖患者在接受腹腔镜袖状胃切除术（LSG）治疗后6个月时肺功能的变化并评估其与炎症介质及脂肪因子的相关性。 方法回顾性分析2019年1月至2020年5月在安徽医科大学第二附属医院行LSG手术的116例肥胖患者的病例资料,比较术前及术后6个月患者体重、体质量指数（BMI）、肺功能、脂肪因子及炎症介质等指标的变化,并进一步分析肺功能的变化与炎症介质及脂肪因子之间相关性。本研究共纳入116例行LSG手术的病态肥胖患者,其中男性53例,女性63例,平均年龄（32.52±6.08）岁,BMI（43.35±7.20） kg/m²。 结果术后6个月体重、BMI、颈围、腰围及腹围较术前均明显降低（P<0.05）,用力肺活量（FVC）、第一秒用力呼气量（FEV1）、第一秒用力肺活量占用力肺活量的百分比（FEV1/FVC）、最大呼气中期流速（MMEF75/25）等肺功能指标在术后6个月均明显改善（P<0.05）。瘦素（leptin）、肿瘤坏死因子-a（TNF-a）、白细胞介素-6（IL-6）、C-反应蛋白（CRP）水平在术后6个月均明显降低（P<0.05）;白细胞介素-10（IL -10）及脂联素（adiponectin）在术后6个月均显著升高（P<0.05）。术前TNF-a、IL-6、CRP、leptin与FEV1呈负相关,adiponectin与FVC呈正相关,而TNF-a、leptin与FVC呈负相关;而在术后6个月,IL-6与FEV1呈负相关;adiponectin与FVC呈显著正相关;而TNF-a与FVC呈负相关。 结论LSG可显著改善肥胖患者肺功能,肺功能的改善可能与术后脂肪因子及炎症介质的水平变化有关。     

老年患者血清25-羟维生素D3水平与哮喘的相关性研究

目的检测老年哮喘患者血清25-羟维生素D3[25(OH)D3]水平,探讨其与哮喘的相关性。方法选择呼吸科确诊为慢性哮喘患者132例,设为病例组,另取健康受试者44例为对照组。通过电化学发光法检测25(OH)D3水平,分析2组血清25(OH)D3水平的差异;同时对患者进行基础肺功能检测,分析肺功能指标与25(OH)D3水平的相关性;依据基础肺功能行支气管激发试验和舒张试验,对25(OH)D3与1秒钟用力呼气容积(FEV1)、FEV1较基础值下降20%时乙酰甲胆碱(MCH)的累积激发剂量[PD20FEV1(MCH)]的相关性进行分析。结果病例组血清25(OH)D3水平显著低于对照组(P0.05);老年哮喘患者血清25(OH)D3水平与FEV1、用力肺活量(FVC)测定值之间无相关性(P0.05),与FEV1/FVC测定值呈正相关(P0.05);病例组支气管激发试验阳性率为46.97%,血清25(OH)D3水平与PD20FEV1(MCH)呈正相关(r=0.67,P0.05);舒张试验阳性率为56.81%,血清25(OH)D3水平与FEV1增加率呈正相关(r=0.54,P0.05)。结论病例组血清25(OH)D3水平显著低于对照组,提示血清25(OH)D3可降低气道高反应性,改善FEV1增加率,表明血清25(OH)D3水平降低可能与老年哮喘的发生有一定相关性。     

白细胞介素-32与慢性阻塞性肺疾病患者肺功能损害的相关性

目的探讨白细胞介素(IL)-32与慢性阻塞性肺疾病(COPD)患者肺功能损害的相关性。方法选取正常人30例,COPD急性加重期(AECOPD)患者30例。AECOPD组接受布地奈德混悬液2 mg雾化吸入,3次/d,治疗1 w。收集正常人及AECOPD患者治疗前后痰液和静脉血,酶联免疫吸附试验(ELISA)检测痰液和血清中IL-32蛋白的表达。检测正常人及AECOPD患者治疗前后肺功能,分析COPD患者IL-32浓度与肺功能损害的相关性。结果 AECOPD组痰液及血清中IL-32浓度明显升高(P0.05),治疗后血清IL-32浓度较治疗前明显降低(P0.05);IL-32浓度与第1秒用力呼气容积(FEV1)占预计值百分比[FEV1(%)]、第1秒用力呼气量占用力肺活量比值(FEV1/FVC)及氧合指数呈负相关关系。结论 IL-32诱导COPD气道炎症,使肺功能损害加重;布地奈德能有效抑制IL-32的表达,起到控制气道炎症、改善肺功能的作用。     

脉冲振荡法在阻塞性通气功能障碍评定中的价值

目的 探讨脉冲振荡法评定阻塞性通气功能障碍的应用价值及其与常规肺通气功能测定的关系.方法 2007年11月至2008年5月,采用德国耶格公司的肺功能仪及产品说明书给出的预计值公式,测定100例(男72例,女28例)门诊和住院患者的FEV1、FVC、5 Hz时气道阻力(R5)、20 Hz时气道阻力(R20)、结构参数图中的中心阻力(Rc)和周边阻力(Rp)的实测值,FEV1、R5和R20占预计值%,以及FEV1/FVC等指标.并对常规和脉冲振荡法测定肺通气功能的指标进行相关分析.结果 所有受试者均获得满意的脉冲振荡测定结果.当FEV1/FVC低于正常时(＜70%),R5和Rp明显升高至(5.3±2.1)和(6.2±2.9)cm H2O·L-1·S-1(1 cm H2O=0.098 kPa),FEV1与R5、Rp呈显著负相关(r值分别为-0.38和-0.47,均P＜0.01),FVC与R5、Rp也呈显著负相关(r值分别为-0.28和-0.37,均P＜0.01).FEV1占预计值%、FVC占预计值%、FEV1/FVC与R5占预计值%均呈显著负相关(r值分别为-0.49、-0.39和-0.43,均P＜0.01).结论 脉冲振荡法的测定指标可用于评估阻塞性通气功能障碍,尤其是R5的诊断价值最大,并且与常规肺通气功能指标之间有良好的相关性.     

Can airway obstruction be estimated by lung auscultation in an emergency room setting?

OBJECTIVE: Lung auscultation is a central part of the physical examination at hospital admission. In this study, the physicians' estimation of airway obstruction by auscultation was determined and compared with the degree of airway obstruction as measured by FEV(1)/FVC values. METHODS: Two hundred and thirty-three patients consecutively admitted to the medical emergency room with chest problems were included. After taking their history, patients were auscultated by an Internal Medicine registrar. The degree of airway obstruction had to be estimated (0=no, 1=mild, 2=moderate and 3=severe obstructed) and then spirometry was performed. Airway obstruction was defined as a ratio of FEV(1)/FVC <70%. The degree of airway obstruction was defined on FEV(1)/FVC as mild (FEV(1)/FVC <70% and >50%), moderate (FEV(1)/FVC <50% >30%) and severe (FEV(1)/FVC <30%). RESULTS: One hundred and thirty-five patients (57.9%) had no sign of airway obstruction (FEV(1)/FVC >70%). Spirometry showed a mild obstruction in 51 patients (21.9%), a moderate obstruction in 27 patients (11.6%) and a severe obstruction in 20 patients (8.6%). There was a weak but significant correlation between FEV(1)/FVC and the auscultation-based estimation of airway obstruction in Internal Medicine Registrars (Spearman's rho=0.328; P<0.001). The sensitivity to detect airway obstruction by lung auscultation was 72.6% and the specificity only 46.3%. Thus, the negative predictive value was 68% and the positive predictive value 51%. In 27 patients (9.7%), airway obstruction was missed by lung auscultation. In these 27 cases, the severity of airway obstruction was mild in 20 patients, moderate in 5 patients and severe in 2 patients. In 82 patients (29.4%) with no sign of airway obstruction (FEV(1)/FVC >70%), airway obstruction was wrongly estimated as mild in 42 patients, as moderate in 34 patients and as severe in 6 patients, respectively. By performing multiple logistic regression, normal lung auscultation was a significant and independent predictor for not having an airway obstruction (OR 2.48 (1.43-4.28); P=0.001). CONCLUSION: Under emergency room conditions, physicians can quite accurately exclude airway obstruction by auscultation. Normal lung auscultation is an independent predictor for not having an airway obstruction. However, airway obstruction is often overestimated by auscultation; thus, spirometry should be performed.     

Predictors of lung function and its decline in mild to moderate COPD in association with gender: results from the Euroscop study

BACKGROUND: There is increasing appreciation of gender differences in COPD but scant data whether risk factors for low lung function differ in men and women. We analysed data from 3 years follow-up in 178 women and 464 men with COPD, participants in the Euroscop Study who were smokers unexposed to inhaled corticosteroids. METHODS: Explanatory variables of gender, age, starting age and pack-years smoking, respiratory symptoms, FEV(1)%FVC and FEV(1)%IVC (clinically important measures of airway obstruction), body mass index (BMI), and change in smoking were included in multiple linear regression models with baseline and change in post-bronchodilator FEV(1) as dependent variables. RESULTS: Reduced baseline FEV(1) was associated with respiratory symptoms in men only. Annual decline in FEV(1) was not associated with respiratory symptoms in either men or women, and was 55 ml less in obese men (BMI 30 kg/m(2)) than men having normal BMI, an effect not seen in women. It was 32 ml faster in women with FEV(1)%FVC相似文献   

Ratio between forced expiratory flow between 25% and 75% of vital capacity and FVC is a determinant of airway reactivity and sensitivity to methacholine

STUDY OBJECTIVE: The ratio between forced expiratory flow between 25% and 75% of vital capacity (FEF(25-75)) and FVC is thought to reflect dysanapsis between airway size and lung size. A low FEF(25-75)/FVC ratio is associated with airway responsiveness to methacholine in middle-aged and older men. The current study was designed to assess this relationship in both male and female subjects over a broader range of ages. STUDY DESIGN: Data analysis of consecutive subjects who had a >or= 20% reduction in FEV(1) after 相似文献   

Socioeconomic status and lung function

Poverty is a major social problem in the United States and throughout much of the world. Poverty and the broader term socioeconomic status (SES) are important determinants of overall health status and many pulmonary diseases. The purpose of this study was to review the medical literature from the past 20 years addressing the relationship between SES and lung function in both children and adults. There is a significant negative correlation between lung function (primarily FEV1 and FVC) and SES. This relationship exists even after adjusting for smoking status, occupational exposures, and race. The magnitude of the effect of low SES on lung function is variable, but FEV1 reductions of >300 mL in men and >200 mL in women have been reported. SES is an important determinant of lung function and an underrecognized contributor to pulmonary disease.     

小气道功能与气道高反应性的相关性分析

目的：分析小气道功能与气道高反应的相关性。方法选取2012年10月至2013年5月于北京友谊医院及北京房山区良乡医院呼吸科门诊就诊的符合纳入及排除标准的临床怀疑哮喘的患者110例,用肺通气功能进行支气管激发试验(BPT),比较 BPT 阳性组与阴性组肺通气肺功能参数及小气道异常率,使用受试者工作特征曲线(ROC 曲线)评估 FEF25/FVC、FEF50/FVC、FEF75/FVC、MMEF/FVC 在 BPT 前后的变化量(△FEF25/FVC、△FEF50/FVC、△FEF75/FVC、△MMEF/FVC)对气道高反应的诊断准确性、敏感度及特异度,对阳性组 PD20-FEV1累积量与△FEF25/FVC、△FEF50/FVC、△FEF75/FVC、△MMEF/FVC进行相关性分析。结果 BPT 前后阳性组 FEV1、FEV1/FVC、FEF25、FEF50、FEF75、MMEF、FEF25/FVC、FEF50/FVC、FEF75/FVC、MMEF/FVC与阴性组比较,差异均有统计学意义(P <0.05)。BPT 前后阳性组小气道异常率与阴性组相比,差异均有统计学意义(χ2=22.482,P =0.000;χ2=25.852,P =0.000)。△FEF25/FVC的曲线下面积(AUC)为0.792[95%CI (0.703~0.881)](P =0.000),△FEF50/FVC的 AUC 为0.767[95%CI (0.677~0.858)](P =0.000),△MMEF/FVC 的 AUC 为0.667[95%CI (0.563~0.771)](P =0.004)。△FEF50/FVC、△MMEF/FVC 与 PD20-FEV1呈正相关(r=0.360,P=0.007;r=0.271,P=0.035)。结论存在气道高反应的患者大小气道功能均明显低于气道反应性正常的患者,存在小气道功能异常的患者BPT可能更易出现阳性结果,小气道功能在激发试验前后的变化可以反映气道高反应性的严重程度。     

脉冲振荡肺功能测定在稳定期慢性阻塞性肺疾病治疗中的应用价值

目的探讨脉冲振荡肺功能测定(IOS)在稳定期慢性阻塞性肺疾病(COPD)临床治疗中的应用价值,及与传统肺功能检测的相关性。方法收集2013年1月至2015年12月我院呼吸科住院的稳定期COPD患者100例作为实验组,根据COPD严重程度分为A、B、C、D四组,A组(轻度)17例,B组(中度)21例,C组(重度)33例,D组(极重度)29例,另选40例健康人作为对照组。所有研究对象入组后进行IOS肺功能测定(Zrs、Fres、R5、R20、X5)和传统肺功能测定(FEV_1、FEV_1/FVC),COPD患者治疗三个月后复诊。结果治疗前后,实验各组与健康组比较,FEV_1、FEV_1/FVC、X5显著降低,Zrs、Fres、R5、R5-R20、R20显著升高;并且COPD越严重Zrs、Fres、R5、R5-R20、R20越高,FEV_1、FEV_1/FVC、X5越低(P0.05);经过治疗后,四个实验组FEV_1、FEV_1/FVC显著升高,Zrs、Fres、R5、R5-R20显著降低(P0.05),X5、R20无明显改变。FEV_1、FEV_1/FVC与Zrs、Fres、R5、R5-R20呈明显负相关(P0.05),与X5呈明显正相关(P0.05),其中FEV_1与Fres的相关性最强(r=-0.765)。结论 IOS肺功能检测指标能客观反映气道阻力,并且与传统肺功能指标有良好的相关性,可以作为一种新的COPD诊断技术在临床上推广使用。     

慢性阻塞性肺疾病诊断中总气道阻力测定的价值探讨

目的探讨脉冲振荡法中总气道阻力（5Hz时气道阻力,R5）在慢性阻塞性肺疾病（COPD）诊断和严重程度分级中的应用价值,并且对与第1秒用力呼气容积／用力肺活量（FEV1／FVC）〈70％和FEV1 pred％〈80％对应的R5％诊断阈值进行探讨。方法应用德国耶格公司生产的Master Screen肺功能仪分别进行常规肺功能和脉冲振荡法测定,选用FEV1、R5实测值,FEV1、R5实测值／预计值百分比,FEV1/FVC百分比等作为分析指标。分析各指标间相关关系,以FEV1／FVC〈70％作为判断COPD患者有无气流受限的“金标准”．以FEVtpred％〈80％作为判断COPD患者严重程度分级的“金标准”以四格表分析决定相应的R5％的诊断灵敏度、特异度和约登指数。结果107例受试者中FEV1／FVC〈70％并符合慢性阻塞性肺疾病诊治指南标准为55例。他们的R5和R5实测值占预计值％明显升高。R5与FEV1呈显著负相关,R5占预计值％与FEV1和FEV1／FVC占预计值％也呈显著负相关。以FEV1／FVC〈70％作为诊断气流受限的“金标准”,分别以R5实测值／预计值〉150％或〉130％为标准的诊断灵敏度为73％、89％;特异度为77％、71％;约登指数为0．5、0．53。以FEV1〈80％作为判断COPD患者严重程度分级的“金标准”,分别以R5实测值／预计值〉150％或〉130％为标准的诊断灵敏度为65％、73％;特异度为88％、82％;约登指数为0．53、0．55。结论在COPD诊断中,以R5实测值／预计值〉130％为标准优于〉150％;合适的诊断阈值尚有待于将来进一步探讨。     

The role of FEV6 in the detection of airway obstruction

OBJECTIVES: There are recent reports regarding the use of forced expiratory volume in 6 s (FEV6) in place of forced expiratory vital capacity (FVC) in the detection of airway obstruction. We aimed to investigate the role of FEV6 in comparison with FVC in the evaluation of airway obstruction. METHODS: The pulmonary function tests (PFT) results of all 5114 patients, who had been tested in the pulmonary function laboratory between 1998 and 2003, were retrospectively analyzed to investigate the relationship between FEV6 and FVC. RESULTS: We have found a mean difference of 95.35+/-121.7 (min=0, max=1050) ml (3.37%) when FVC and FEV6 values (FVC-FEV6) of all cases were compared. This difference was found to be higher (180 ml, 7.3%) in patients with airway obstruction. When FEV1/FVC is taken as the gold standard, FEV1/FEV6 had negative predictive value of 92.24% and a sensitivity of 86.09% in the detection of airway obstruction. CONCLUSIONS: Although it is easier to use FEV6 in place of FVC, relatively low sensitivity in that setting may result in the underestimation of airway obstruction. This drawback should be kept in mind when FEV6 is utilized to detect airway obstruction.     

FEV1/FEV6 and FEV6 as an alternative for FEV1/FVC and FVC in the spirometric detection of airway obstruction and restriction

STUDY OBJECTIVES: To evaluate the use of the FEV(1)/forced expiratory volume at 6 s of exhalation (FEV(6)) ratio and FEV(6) as an alternative for FEV(1)/FVC and FVC in the detection of airway obstruction and lung restriction, respectively. SETTING: Pulmonary function laboratory of the Academic Hospital of the Free University of Brussels. PARTICIPANTS: A total of 11,676 spirometric examinations were analyzed on subjects with the following characteristics: white race; 20 to 80 years of age; 7,010 men and 4,666 women; and able to exhale for at least 6 s. METHODS: Published reference equations were used to determine lower limits of normal (LLN) for FEV(6), FVC, FEV(1)/FEV(6), and FEV(1)/FVC. We considered a subject to have obstruction if FEV(1)/FVC was below its LLN. A restrictive spirometric pattern was defined as FVC below its LLN, in the absence of obstruction. From these data, sensitivity and specificity of FEV(1)/FEV(6) and FEV(6) were calculated. RESULTS: For the spirometric diagnosis of airway obstruction, FEV(1)/FEV(6) sensitivity was 94.0% and specificity was 93.1%; the positive predictive value (PPV) and negative predictive value (NPV) were 89.8% and 96.0%, respectively. The prevalence of obstruction in the entire study population was 39.5%. For the spirometric detection of a restrictive pattern, FEV(6) sensitivity was 83.2% and specificity was 99.6%; the PPVs and NPVs were 97.4% and 96.9%, respectively. The prevalence of a restrictive pattern was 15.7%. Similar results were obtained for male and female subjects. When diagnostic interpretation differed between the two indexes, measured values were close to the LLN. CONCLUSIONS: The FEV(1)/FEV(6) ratio can be used as a valid alternative for FEV(1)/FVC in the diagnosis of airway obstruction, especially for screening purposes in high-risk populations for COPD in primary care. In addition, FEV(6) is an acceptable surrogate for FVC in the detection of a spirometric restrictive pattern. Using FEV(6) instead of FVC has the advantage that the end of a spirometric examination is more explicitly defined and is easier to achieve.